1. Technical Field
The present invention relates to heads used to write and retrieve information on magnetic storage tape media. More particularly, the invention concerns a method for embedding a chip that has active elements, in a substrate, to form a composite air bearing surface that may be used, for example, in a tape head.
2. Description of Related Art
Magnetic tape is widely used for storing data in computing systems. Tape heads are used for writing information to the tape and reading information from the tape. A tape head typically includes two modules that each have a plurality of reading and writing elements, that may be called active elements. In each module, the reading and writing elements are formed in a substrate that has a smooth air bearing surface (ABS) which makes contact with and supports the flexible tape as it travels. This type of tape head may be called a contact recording tape head. To minimize the occurrence of decreased signals from spacing losses, damage to the tape, and other problems, the air bearing surface of each module must be very smooth, so that the tape can pass over each module in close proximity to the reading and writing elements. Because of its degree of smoothness, an air bearing surface may be referred to as being optically polished.
Because the reading and writing elements in each module span only a small portion of the tape width, during operation the tape head is moved laterally so that the substrate in each module moves laterally across the tape to line up the reading and writing elements with the tracks on the tape that are being read from or written to. Consequently, the substrates are wider than the width of the tape, and are considerably wider than the portion of the tape spanned by the reading and writing elements, to maintain support of the tape surface and to avoid potentially tearing the tape with sharp edges while lining up the reading and writing elements with tracks that are not in the center of the tape.
Traditionally, the reading and writing elements and the substrate of a module are formed in a semiconductor wafer. Forming the substrate in the wafer requires a much larger area of the wafer than is required for the reading and writing elements. Due to the high cost of wafer space, forming the substrate in the wafer substantially increases the cost of making a module. Consequently, existing methods for making tape heads are not completely cost effective.